38th parallelMilitary vehicles crossing the 38th parallel during the Korean War.(more)NARASome borders, like that between the United States and Canada, are peaceful ones. Others are places of conflict caused by rivalries between countries or peoples, disputes over national resources, or disagreements about the past. Eight of the most contentious borders in the world are described in this list.

　　Senkaku (Diaoyu) islands, East China Sea

　　the East China, South China, and Yellow seasEncyclopædia Britannica, Inc.On the surface, the Senkaku (Chinese: Diaoyu) islands seem to offer very little to fight over beyond rocks and water. The dispute over these islands, controlled by Japan and claimed by China, intensified after oil and gas fields were found underneath. In 2012 the sale of one of the islands by a wealthy Japanese family to the Japanese government enraged the Chinese population and led to massive anti-Japanese riots. Considering the growing power and assertiveness of China in Asia, many experts warn that the tension over the Senkaku islands could develop into a more serious conflict.

　　Kuril Islands

　　Kraternaya BayThe summit of a partially submerged volcano forms the outline of Kraternaya Bay, Yankich Island, in the Kuril Islands of Russia.(more)Michael V. ProppThe dispute over this volcano-intensive archipelago of 56 islands is the primary reason Japan and Russia have never signed a peace treaty to formalize the end of World War II. At the end of the war, the Soviet Union invaded the Kuril Islands, some of which Imperial Russia had previously controlled. While the transfer of the islands to the Soviet Union was included in the Yalta agreements, Japan continued to claim historical rights to the southernmost islands.

　　Lest we forget, the Korean War never really came to an end. South and North Korea signed an armistice but no peace treaty, and the two countries continued to face each other in a nerve-racking geopolitical standstill.

　　Western Sahara

　　sand dunes of the SaharaSand dunes of the Sahara desert.The indigenous inhabitants of Western Sahara, the Saharawis, have fought for their independence against Morocco since the 1970s. Their organization, the Polisario Front, has waged an armed insurgency but also shown its readiness to sit at the negotiation table. In 1991, both parties agreed to a peace proposal under the auspices of the United Nations. The peace proposal specified a referendum for the indigenous Saharawi to decide whether they wanted an independent Western Sahara under Polisario Front leadership or whether the territory would officially become part of Morocco. Peace, however, was not yet in the cards, as Morocco moved tens of thousands of settlers into the territory to influence the referendum results, and Polisario soldiers resumed their armed campaigns. Still, hope for a peaceful resolution remained.

　　Antarctica

　　emperor penguinEmperor penguins in Antarctica.A number of countries, including the United Kingdom, France, and Argentina, have made claims over the frozen continent of Antarctica, but these claims have not been recognized by the international community since the signature of the Antarctica Treaty in 1959. The treaty forbade countries from taking possession of any part of Antarctica with these solemn words: "in the interest of all mankind that Antarctica shall continue forever to be used exclusively for peaceful purposes and shall not become the scene or object of international discord.” Some experts believe the discovery of precious natural resources could change the equation and revive countries’ claims to Antarctica. No word yet on a penguin independence movement.

　　Impossible to ignore, the Israel-Palestine conflict is a source of insecurity for the Middle East and for the world at large.

　　Somaliland

　　In 1991 the self-proclaimed Republic of Somaliland, in the northwest part of Somalia, asserted its independence from the rest of the country. In 1998 a region in the northeast, the Puntland, declared itself “autonomous.”Encyclopædia Britannica, Inc.The modern borders of Africa are in large part the result of the competition between European colonial powers such as Britain and France for the control of the continent. During World War II, all the Somali territories were unified under British military administration, with the exception of French Somaliland. This process of unification continued after Somalia gained its independence in 1960. At the end of the 1980s, however, the country was shattered by the beginning of a decades-long civil war, and Somaliland, a region in the north on the coast of the Gulf of Aden, declared its independence in 1991. The Republic of Somaliland, however, remained unrecognized by the international community.

　　Taiwan

　　TaiwanEncyclopædia Britannica, Inc.After the Japanese defeat in World War II, the island of Taiwan reverted to China. The Chinese government itself, however, was soon overthrown on the mainland by the People’s Liberation Army of Mao Zedong, and the new communist state took the name the People’s Republic of China. The nationalist government of Chiang Kai-shek went into exile on the island, which it continued to rule as the Republic of China (ROC). While the People’s Republic of China claims sovereignty over the “rogue province” of Taiwan, the ROC still regards itself as the legitimate government of China on both sides of the Taiwan Strait.